Can neonates born at 34 weeks be classified as late preterm?

Objectives: In recent years, much attention has been given to infants born prematurely, at 34 0/7 to 36 6/7 weeks of gestation (WG), which have been classified as ‘late preterm’. Neonates from that subgroup are less physiologically and metabolically mature than term infants. The aim of the study was to determine whether infants born at 34WG can be classified as ‘late preterm’ or ‘preterm’ newborns. Material and methods: A total of 141 newborns were included in the study: 25 born ≤ 33WG, 53 late-preterm newborns, and 63 term infants. Cord-blood neutrophil gelatinase-associated lipocalin (NGAL) and creatinine concentrations were measured in all newborns. Also, the incidence of clinical complications in the early adaptive period during hospitalization was evaluated. Results: Higher NGAL concentration was noted among preterm newborns as compared to late-preterm neonates (p < 0.05), and term newborns (p < 0.05), especially in children born at 34WG as compared to 35WG (p < 0.001). However, no differences in NGAL concentration were found between neonates born at 35WG and 36WG, as well as children born at 36WG and term infants. A relationship between umbilical NGAL levels and gestational age was observed. Additionally, a statistically significant difference was found in the incidence of respiratory distress syndrome (p < 0.05) and infections (p < 0.05) among neonates born at 34WG as compared to 35WG. Conclusions: Late preterm neonates should be defined as ‘preterm’ between 35 0/7 and 36 6/7 WG. Infants born at 34WG should be included in the preterm group

Computer- and NMR-aided design of small-molecule inhibitors of the Hub1 protein

By binding to the spliceosomal protein Snu66, the human ubiquitin-like protein Hub1 is a modulator of the spliceosome performance and facilitates alternative splicing. Small molecules that bind to Hub1 would be of interest to study the protein-protein interaction of Hub1/Snu66, which is linked to several human pathologies, such as hypercholesterolemia, premature aging, neurodegenerative diseases, and cancer. To identify small molecule ligands for Hub1, we used the interface analysis, peptide modeling of the Hub1/Snu66 interaction and the fragment-based NMR screening. Fragment-based NMR screening has not proven sufficient to unambiguously search for fragments that bind to the Hub1 protein. This was because the Snu66 binding pocket of Hub1 is occupied by pH-sensitive residues, making it difficult to distinguish between pH-induced NMR shifts and actual binding events. The NMR analyses were therefore verified experimentally by microscale thermophoresis and by NMR pH titration experiments. Our study found two small peptides that showed binding to Hub1. These peptides are the first small-molecule ligands reported to interact with the Hub1 protein

Discovery of inhibitory fragments that selectively target Spire2−FMN2 interaction

Here, we report the fragment-based drug discovery of potent and selective fragments that disrupt the Spire2–FMN2 but not the Spire1–FMN2 interaction. Hit fragments were identified in a differential scanning fluorimetry-based screen of an in-house library of 755 compounds and subsequently validated in multiple orthogonal biophysical assays, including fluorescence polarization, microscale thermophoresis, and 1H–15N HSQC nuclear magnetic resonance. Extensive structure–activity relationships combined with molecular docking followed by chemical optimization led to the discovery of compound 13, which exhibits micromolar potency and high ligand efficiency (LE = 0.38). Therefore, this fragment represents a validated starting point for the future development of selective chemical probes targeting the Spire2–FMN2 interaction

Exploring the Surface of the Ectodomain of the PD-L1 Immune Checkpoint with Small-Molecule Fragments

Development of small molecules targeting the PD-L1/PD-1 interface is advancing both in industry and academia, but only a few have reached early-stage clinical trials. Here, we take a closer look at the general druggability of PD-L1 using in silico hot spot mapping and nuclear magnetic resonance (NMR)-based characterization. We found that the conformational elasticity of the PD-L1 surface strongly influences the formation of hot spots. We deconstructed several generations of known inhibitors into fragments and examined their binding properties using differential scanning fluorimetry (DSF) and protein-based nuclear magnetic resonance (NMR). These biophysical analyses showed that not all fragments bind to the PD-L1 ectodomain despite having the biphenyl scaffold. Although most of the binding fragments induced PD-L1 oligomerization, two compounds, TAH35 and TAH36, retain the monomeric state of proteins upon binding. Additionally, the presence of the entire ectodomain did not affect the binding of the hit compounds and dimerization of PD-L1. The data demonstrated here provide important information on the PD-L1 druggability and the structure-activity relationship of the biphenyl core moiety and therefore may aid in the design of novel inhibitors and focused fragment libraries for PD-L1.This research has been supported by Grants Maestro 2017/26/A/ST5/00572 (to T.A.H.) , Sonata UMO-2020/39/D/ST4/01344 (to E.S.) , Preludium UMO-2021/41/N/ST4/03485 (to M.Z.) , and Preludium UMO-2020/37/N/ST4/02691 (to D.M.) from the National Science Centre, Poland. X.d.C. thanks the Basque Country Government for the predoctoral and EGONLABUR grants

Effect of acute sprint exercise on myokines and food intake hormones in young healthy men

Physical exercise is known to influence hormonal mediators of appetite, but the effect of short-term maximal intensity exercise on plasma levels of appetite hormones and cytokines has been little studied. We investigated the effect of a 30 s Wingate Test, followed by a postprandial period, on appetite sensations, food intake, and appetite hormones. Twenty-six physically active young males rated their subjective feelings of hunger, prospective food consumption, and fatigue on visual analogue scales at baseline, after exercise was completed, and during the postprandial period. Blood samples were obtained for the measurement of nesfatin-1, ghrelin, leptin, insulin, pancreatic polypeptide (PP), human growth factor (hGH) and cytokine interleukin-6 (IL-6), irisin and plasma lactate concentrations, at 30 min before exercise, immediately (210 s) after exercise, and 30 min following a meal and at corresponding times in control sedentary males without ad libitum meal intake, respectively. Appetite perceptions and food intake were decreased in response to exercise. Plasma levels of irisin, IL-6, lactate, nesfatin-1 and ghrelin was increased after exercise and then it was returned to postprandial/control period in both groups. A significant rise in plasma insulin, hGH and PP levels after exercise was observed while meal intake potentiated this response. In conclusion, an acute short-term fatiguing exercise can transiently suppress hunger sensations and food intake in humans. We postulate that this physiological response involves exercise-induced alterations in plasma hormones and the release of myokines such as irisin and IL-6, and supports the notion of existence of the skeletal muscle-brain-gut axis. Nevertheless, the detailed relationship between acute exercise releasing myokines, appetite sensations and impairment of this axis leading to several diseases should be further examined

Hitting on the move:Targeting intrinsically disordered protein states of the MDM2-p53 interaction

Intrinsically disordered proteins are an emerging class of proteins without a folded structure and currently disorder-based drug targeting remains a challenge. p53 is the principal regulator of cell division and growth whereas MDM2 consists its main negative regulator. The MDM2-p53 recognition is a dynamic and multistage process that amongst other, employs the dissociation of a transient α-helical N-terminal ''lid'' segment of MDM2 from the proximity of the p53-complementary interface. Several small molecule inhibitors have been reported to inhibit the formation of the p53-MDM2 complex with the vast majority mimicking the p53 residues Phe19, Trp23 and Leu26. Recently, we have described the transit from the 3-point to 4-point pharmacophore model stabilizing this intrinsically disordered N-terminus by increasing the binding affinity by a factor of 3. Therefore, we performed a thorough SAR analysis, including chiral separation of key compound which was evaluated by FP and 2D NMR. Finally, p53-specific anti-cancer activity towards p53-wild-type cancer cells was observed for several representative compounds

Nutlin-3a-aa: Improving the Bioactivity of a p53/MDM2 Interaction Inhibitor by Introducing a Solvent-Exposed Methylene Group

Nutlin-3a is a reversible inhibitor of the p53/MDM2 interaction. We have synthesized the derivative Nutlin-3a-aa bearing an additional exocyclic methylene group in the piperazinone moiety. Nutlin-3a-aa is more active than Nutlin-3a against purified wild-type MDM2, and is more effective at increasing p53 levels and releasing transcription of p53 target genes from MDM2-induced repression. X-ray analysis of wild-type MDM2-bound Nutlin-3a-aa indicated that the orientation of its modified piperazinone ring was altered in comparison to the piperazinone ring of MDM2-bound Nutlin-3a, with the exocyclic methylene group of Nutlin-3a-aa pointing away from the protein surface. Our data point to the introduction of exocyclic methylene groups as a useful approach by which to tailor the conformation of bioactive molecules for improved biological activity.This work was generously supported by the Deutsche Forschungsgemeinschaft (BE 4572/3-1 to T.B.). We extend our thanks to Barbara Klüver, Katrin Eckhardt, Nadiya Brovchenko, and Domenique Herbstritt for experimental support. Parts of the data described in this manuscript have been published in the dissertation of Florian Nietzold (Leipzig University, 2019).31 In addition, this work was financially supported by the National Science Centre, Poland (NCN) under Grant Symphony 2014/12/W/NZ1/00457 (to T.A.H). We thank HZB for the allocation of synchrotron radiation beamtime. We acknowledge the MCB Structural Biology Core Facility (supported by the TEAM TECH CORE FACILITY/2017-4/6 grant from the Foundation for Polish Science) for valuable support. Open Access funding enabled and organized by Projekt DEAL

Design of indole- and MCR-based macrocycles as p53-MDM2 antagonists

Macrocycles were designed to antagonize the protein-protein interaction p53-MDM2 based on the three-finger pharmacophore F19W23L25. The synthesis was accomplished by a rapid, one-pot synthesis of indole-based macrocycles based on Ugi macrocyclization. The reaction of 12 different α,ω-amino acids and different indole-3-carboxaldehyde derivatives afforded a unique library of macrocycles otherwise difficult to access. Screening of the library for p53-MDM2 inhibition by fluorescence polarization and 1H,15N HSQC NMR measurements confirm MDM2 binding